Directional Water Collection in Nanopore Networks

GIMENEZ, ROCIO; BELLINO, MARTÍN GONZALO; BERLI, CLAUDIO LUIS ALBERTO

ACS Omega

AMERICAN CHEMICAL SOCIETY

Año: 2018 vol. 3 p. 16040 - 16045

2470-1343

The development of artificial nanosystems that mimic directionalwater-collecting ability of evolved biological surfaces is eagerly awaited.Here we report a new type of addressable water collection that is induced bycoupling both vapor gradients, like a road drawn, and the temperature-tunedcondensation in nanopores as step signals. What distinguishes the motiondescribed here from the motions reported earlier is the fact that neither bulkliquid infiltration nor displacement of droplet is required. Instead, the motionresults from a scanned water capture because of the temperature-dependent condensation command acting on the vapor pressure gradient track originated by a droplet without a bulk fluidic connection with a mesoporous film. This novel working principle demands only a small-range surface temperatura control, which was entirely generated by a thermoelectric cell integrated to the mesoporous substrates. The strategy opens the route to achieving precise control over wetting location (from a few to hundreds of micrometers) and hence over the direction of water collected by these widely employed nanomaterials. Furthermore, as water is collected from condensation into the pores, the system naturally involves purification and subsequent delivery of clean water, which provides an added value to the proposed strategy.